Centrifugal sieving machine



Sept. 18, 1934. BIFFAR v 1,973,864

GENTRIFUGAL SIEVING MACHINE I Filed ma 25, 1932 2 Sheets-Sheet 1 m srunIIIIIIIII IN I III! Sept. 18, '1934.

A. BIFFAR CENTRIFUGAL SIEVING MACHINE Filed May 25, 1932 2 Sheets-Sheet2 UNITED STATES PATENT OFFICE CENTRIFUGAL SIEVING MACHINE AndreasBilfar, Miltenberg-on-the-Main, Germany Application May 25, 1932, SerialNo. 613,479 In Germany September 5, 1931 11 Claims. (Cl. 9234) I havefiled an application in Germany, on the the efficiency of the machine isimpaired and th September, 1931; in Sweden, on the 5th that aninsufficient quantity of fibre passes November, 1931; and in Finland onthe 19th through the sieve, a considerable part of the lat-, November,1931. ter passing into the waste material.

5 The present invention relates to a, centrifugal In contradistinctionto this, according to the 60 sieving machine, particularly for paperpulp, cel-- invention, the sievingspace bounded by the cylinlulose, woodpulp or other fibrous materials susdrical sieve and the drum is arrangedso as to pended in liquid. Centrifugal sieving machines constitute auniform sieving zone which is of of this kind are usually provided witha stationthe same cross section at all parts and to which arycylindrical sieve into which the suspended the water is supplied fromthe drum uniformly 65 fibrous material and water for thinning purposesover its whole length. are introduced and in which a centrifugatingFurther characteristic features of the invenwheel or a drum providedwith centrifugating tion will be elucidated in the followingdescripblades rotates. The centrifugating blades drive tion withreference to the accompanying drawthe fibrous material through thecylindrical sieve. ings which illustrate by way of example some 70 Theinvention relates more particularly to cenconstructional forms of acentrifugal sieving matrifugal sieving machines provided with a cenchineaccording to the invention. trifugating drum arranged within thecylindri- Referring to the drawings: cal sieve, wherein the fibrousmaterial and the wa- Fig. 1 shows one constructional form of a centerare introduced into the machine in the longitrifugal sieving machine.according to the inven- 75 tudinal or axial direction of the cylindricalsieve tion in vertical longitudinal section, in opposite directions, thefibrous material being Fig. 2 shows the centrifugating drum and theintroduced into the space between the sieve and cylindrical sieveappertaining thereto in vertical the drum whilst the water is introducedinto the, cross section,

drum itself- The walls of the drum a e pro- Figs. 3 and 4 show detailsof different con- V d with perforations passages t ugh structional formsof the centrifugating drum in which the water passes into the spacebetween vertical cross section, the drum and the sieve and thins downthe ma- 'Fig. 5 is a section taken on line V-V of Fig. 1, terial. In theknown Centrifugal sieving 1113- Fig. 6 is an elevation of acentrifugating wheel chines of this kind the drum is constructed of forthe introduction of the material (direction 5 conical form and increasesin breadth from the X) indicated in Fig. 1, side of the machine at whichthe fibrous mate- Fig. 7 is an elevation of the centrifugating rial isintroduced into the Siev t w the DDO- wheel for the introduction of thewater (direcsite side at which the water is introduced into tion Y)indicated in Fig, 1,

the drum. The material to be sieved passes in Fig, 8 shows to a, largerscale a, detail of Fig, 1,

the longitudinal direction of the sieve into the and v space between thedrum and the sieve and moves Fig. 9 shows another constructional form ofa towards the side of the sieve at which the water sieving machineaccording to the invention, is introduced into the drum. Inasmuch as theThe reference numeral 1 denotesa, housing in 4.0 drum increases inbreadth in the same direction which a stationary cylindrical sieve 2 isarranged. the spac between the sieve and the drum on Through thecylindrical sieve a shaft ljournalled the side at which the water isintroduced is subin the housing at 3 provided with driving stantiallynarrower than on the side at which pulley 5 passes co axiauy on the h ft4 a the material enters the sieve. As a consequence trifugating drum 6is mounted which is provided 45 of this t material 9 9 denser at i Partwith external blades '1 and internal blades s. of the slew T thmnmgwater.enter.s directly In the wall of the drum 6 perforations orpassages only into this part of the sieve masmuch as the drum is onlyprovided at its broader 9 q' t be ed is introduced into part withperforations which allow the water to th i 9 slev h v 1 t 10 f tratefrom the drum into the space between Slevmg i q 6 mm 50 Dene WhlCh itpasses in axial direction into the space the drum and the 516% betweenthe sieve 2 and the centrifugating drum As a result of this the fibrousmaterial is not uniformly treated along the length of the i 6. The wateris introduced through an 1nlet 11 ing zone comprising the space betweenthe drum provided at the other end of the sieving machine, 55 and thesieve. The consequence of this is that and passes in the oppositedirection to the mateno rial but likewise in axial direction into thedrum itself and from this latter through the passages 9 into thecylindrical sieve. The sieved material is collected below the sieve andwithdrawn whilst the residual material which contains the splinters andknots and does not pass through the sieve is led off through an outlet10a.

The centrifugating blades are arranged on the centrifugating drum inpairs each consisting of one external blade '7 and one inner blade 8. Asshown in Fig. 2 the inner blade 8 is displaced slightly backwards in thedirection of rotation of the drum with regard to. the external blade 7.The passage 9 in the drum is arranged in such manner that it is locatedin front of the internal blade but behind the external blade, whichlatter is fixed to the drum by means of a flange provided with acorresponding passage. In the constructional form according to Fig. 2the passage in the drum and in the flange runs in a backwardly inclineddirection from the interior to the exterior.

In the constructional form shown in Fig. 3 the internal blade and theexternal blade are arranged in the same plane and the passage is locatedin front of them both. In the constructional form shown in Fig. 4 theouter blade which extends beyond the inner blade is provided with aradial bore 12 through which thewater flows outwards from the drum.

The passages in the wall of the drum are adapted, as shown in Fig. 1, tobe covered, partly covered or entirely uncovered by means of slidemembers 13 provided with openings 14 which can be brought into entire.or partial register with the openings 9 according to the adjustment. of

the slide members 13. To the slide members levers 15 are pivotallyconnected which are journalled in brackets 16 provided on the hub 17 ofthe drum and are, forked at their free ends, the forked parts engagingpins 18 provided on the periphery of an internally threaded member 19.The said internally threaded member co-operates with a screw spindle 20which is mounted in the interior of the hollow drum shaft so as to berotatable co-axially with the latter. In the hollow drum shaft 4 slitsare provided for the passage. of the levers 15. The spindle can beoperatedby means of a hand wheel 21 mounted on itse'xternal projectingend.

The above described constructional form of the device for the adjustmentof the slides is employed at the same time in the present case for theadjustment of the external blades which are arranged so as to beradially adjustable according to the invention. In the constructionalform of the sieving machine illustrated in the drawings the externalblades are divided longitudinally into two parts. At their front partthe blades are rigidly attached to the periphery of the drum. The rearpart of the blade is pivotally connected at the end nearest to thematerial inlet at 22 to the front part of the blade so as to be capableof swinging, whilst the other end of the rear part of the blade isconnected to a linkage 23, 23'. The said linkage is pivotally connectedat its other end with the aforesaid internally threaded member or with asecond threaded member provided on the spindle 20, so that ondisplacement of the slide member the outer blade is simultaneouslydisplaced.

For the purpose of regulating the supply of the material and waterrespectively a float 24 (Fig. 1) is provided which floats in theunsieved waste material collected below the sieving machine or atanother suitable place in a container 25. The container is connected toan over-flow vessel 26, the over-flow into the saidvessel being adjustedby means of a slide 2'7.

To the float 24 a linkage 28, 29, 30, 31 is connected which is pivotallyconnected at its other end to slides 32 and 33 provided in the materialinlet 10 and the water inlet 11 respectively. When the quantity ofmaterial in the container 25 increases the float rises and therebycauses the slide 33 in the water inlet 11' to move so as to increase thesize of the inlet passage whilst at the same time causing the slide 32in the material inlet 10 to move so. as to throttle the material inlet.When the amountof material in the container 25 decreases the float sinksand the reverse action takes place.

The material and the water are forced through the machine by means ofcentrifugating wheels 34 and 35 which are arranged in front of the sieveand in front of the drum respectively. Whilst the blades of the drumextend entirely in an axial direction, the blades of the wheels 34, 35are inclined to the axial direction so as to obtain a better feedingaction.

In the constructional form shown in Fig. 9 the fibrous material ispassed through a pipe system arranged behind a sand collector 36. Thesaid pipe system comprises a horizontal shaft 3'? on which a long pipe38 is mounted in such manner that a free space remains between the shaftand the pipe. On the periphery of the said pipe blades 39 are mounted.The shaft 37 together with the pipe 38 passes through a stationarytubular sieve 40. The pipe 38 provided with blades is connected to theinlet 11 for the water in such manner thatthe latter can pass into thesaid pipe 38 and thence through the passages into the space between thepipe 38 and the sieve 40. The fibrous material passes from the inlet 10into the interior of the tubular sieve 40. With this arrangement thefibrous material is effectively washed and sorted or sifted. The fibrousmaterial passes out of the pipe system through the sieve and isdischarged underneath.

The sorting or sifting action can be still further improved by providingpumps in the pipe system, one of which is adapted to force the.

material into the space inside the sieve, whilst the other forces thewater into the rotating centrifugating pipe.

With this constructional form of. the invention the sorting or shiftingis substantially simplified inasmuchas the pipe system can be made ofany desired length and it is consequently unnecessary to erect a numberof sieving machines together with the material and water supply anddischarge conduits appertaining thereto so that the costs of theinstallation are substantially lower.

I claim:

1. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending over the wholelength of said sieve; blades on said drum running longitudinallythereof; a sieving zone bounded by said sieve and said drum-and havingthe same cross section at all parts; means for rotating said drum; meansfor supplying maof said drum, the water passing through said passagesinto said zone and being distributed uniformly over the whole lengththereof; and slide members arranged on the periphery of said drum andadapted to control the size of said passages.

2. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axiallyin counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve coaxially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; longitudinalblades on said drum; a sieving zone bounded by said sieve and said drumand having the same cross section at all parts; means for supplyingmaterial to be sieved to said zone; means for supplying water to theinterior of said drum; passages distributed uniformly over the peripheryof said drum, the water passing through said passages into said zone andbeing distributed uniformly over the periphery of said drum; a threadedspindle arranged in said hollow shaft and rotating co-axially therewith,said spindle being adjustable from the exterior; an internally threadedmember co-opcrating with said spindle; and slide members arranged on theperiphery of said drum and coupled with said internally threaded member,said slide members being adapted tocontrol the size of said passages.

3. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending'over the wholelength of said sieve; internal blades on said drum runninglongitudinally thereof; radially adjustable external blades on said drumrunning longitudinally thereof; a sieving zone bounded by said sieve andsaid drum and having the same cross section at all parts; means forrotating said drum; means for supplying material to be sieved to saidsieving zone; means for supplying water to the interior of said drum;passages distributed uniformly over the periphery of said drum, thewater passing through said passages into said zone and being distributeduniformly over the whole length thereof; and slide members arranged onthe periphery of said drum and adapted to control the size of saidpassages.

4. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve coaxially therewith and extending over .the wholelength of said sieve; a sieving zone bounded by said sieve and said drumand having the same cross section at all parts; means for rotating saiddrum; means for supplying material to be sieved to said sieving zone;means for supplying water to the interior of said drum; passagesdistributed uniformly over the periphery of said drum, the water passingthrough said passages into said zone and being distributed uniformlyover the whole length thereof; slide members arranged on the peripheryof said drum and adapted .to cone trol the size of'said passages;internal blades on said drum running longitudinally thereof; externalblades on said drum running longitudinally thereof and pivoted at theend adjacent to said means for supplying material; and a device arrangedat the other end of said external blades for displacing them radially,

5. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve coaxially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; longitudinalinternal and external blades on said drum; a sieving zone bounded bysaid sieve and said drum and having the same cross section to all parts;means for supplying material to be sieved to said zone; means forsupplying water to the interior of said drum; passages dis tributeduniformly over the periphery of said drum, the water passing throughsaid passages into said zone and being distributed uniformlyover theperiphery of said drum; a threaded spindle arranged in said hollow shaftand rotating coaxially therewith, said spindle being adjustable from theexterior; an internally threaded member co-operating with said spindle;slide members arranged on the periphery of said drum and coupled withsaid internally threaded member, said slide members being adapted tocontrol the size of said passages; and means for radially adjusting saidexternal blades, comprising a linkage coupling said external blades withsaid internally threaded member.

6. A horizontal centrifugal sieving machine, wherein the material to besieved-is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; internal andexternal longitudinal blades arranged in pairs on said drum; a sievingzone bounded by said sieve and said drum and having 1 5 the same crosssection at all parts; means for supplying material to be sieved to saidzone; means for supplying water to the interior of said drum; passagesdistributed uniformly over the periphery of said drum, the water passingthrough 2 said passages into said zone and being distributed uniformlyover the periphery of said drum; a threaded spindle arranged in saidhollow shaft and rotating co-axially therewith, said spindle beingadjustable from the exterior; an internally threaded member co-operatingwith said spindle; and slide members arranged on the periphery of saiddrum and coupled with said internally threaded member, said slidemembers being adapted to control the size of said passages.

7. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current-to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; a sieving zonebounded by said sieve and said drum and having the same cross section atall parts; means for supplying material to be sieved to said zone; meansfor supplying water to the interior of said drum; passages distributeduniformly over the periphery of said drum, the water passing throughsaid passages into said zone and being distributed uniformly over theperiphery of said drum; a threaded spindle arranged in said hollow shaftand rotating co-axially therewith, said spindle being adjustable fromthe exterior; an internally threaded member co-opcrating with saidspindle; slide members arranged 5 on the periphery of said drum andcoupled with said internally threaded member, said slide members beingadapted to control the size of said passages; and internaland externalblades arranged in pairs on said drum, the internal blade of each pairbeing staggered with regard to-the corresponding external blade in suchmanner that said passages open at their inner ends in front of theinternal blades and at their outer ends behind the external blades.

8. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; a sieving zonebounded by said sieve and said drum and having the same cross section atall parts; means for supplying material to be sieved to said zone; meansfor supplying water to the interior of said drum; passages distributeduniformly over the periphery of said drum, the water passing throughsaid passages into said zone and being distributed uniformly over theperiphery of said drum; a threaded spindle arranged in said hollow shaftand rotating coaxially therewith, said spindle being adjustable from theexterior; an internally threaded member co-operating with said spindle;slide members arranged on the pe-' riphery of said drum and coupled withsaid internally threaded member, said slide members being adapted tocontrol the size of said passages; and internal and external bladesarranged in pairs on said drum, the internal blade of each pair beingstaggered with regard to the corresponding external blade in such mannerthat said passages open at their inner ends in front of the internalblades and at their outer ends into bores provided in the said externalblades.

9. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve coaxially therewith and extending over the wholelength thereof; a hollow shaft 'for rotating said drum; longitudinalradial blades on said drum; a sieving zone bounded by said sieve andsaid drum and having the same cross section at all parts; centrifugatingblades for feeding material to be sieved to said zone, said blades beingarranged in front of said drum and inclined to the axis of said hollowshaft; centrifugating blades for feeding water to the interior of saiddrum, said blades being arranged behind said drum and inclined to theaxis of said hollow shaft; passages distributed uniformly over theperiphery of said drum, the water passing through said passages intosaid zone and being distributed uniformly over the periphery of saiddrum; a threaded spindle arranged in said hollow shaft and rotatingco-axially therewith, said spindle being adjustable from the exterior;an internally threaded member co-operating with said spindle; and slidemembers arranged on the periphery of said drum and coupled with saidinternally threaded member, said slide members being adapted to controlthe size of said passages.

10. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a drum arranged in saidsieve co-axially therewith; a uniform sieving zone bounded by said sieveand said drum and having the same cross section at all parts; means forrotating said drum; means for supplying material to be sieved to saidsieving zone; means for supplying water to the interior of said drum,the water passing through said drum to said zone being distributeduniformly over the whole length of said zone; a container for thereception of the overflow 0f non-sieved material arranged below theapparatus; a float in said container; and throttling devices controlledby said float and associated with said means for supplying material tobe sieved and said means for supplying water.

11. A horizontal centrifugal sieving machine, wherein the material to besieved is introduced axially in counter current to a stream of water,comprising in combination: a cylindrical sieve; a cylindrical drumarranged in said sieve co-axially therewith and extending over the wholelength thereof; a hollow shaft for rotating said drum; longitudinalblades on said drum; a sieving zone bounded by said sieve and said drumand 110 having the same cross section at all parts; means for supplyingmaterial to be sieved to said zone; means for supplying water to theinterior of said drum; passages distributed uniformly over the peripheryof said drum, the Water passing through said passages into said zone andbeing distributed uniformly over the periphery of said drum; a threadedspindle arranged in said hollow shaft and rotating co-axially therewith,said spindle being adjustable from the exterior; an internally threadedmember co-operating with said spindle; slide members arranged on theperiphery of said drum and coupled with said internally threaded member,said slide members being adapted to control the size of said passages; acontainer for the reception of the overflow of non-sieved materialarranged below the apparatus; a float in said container; and throttlingmeans associated with said means for supplying material to be sieved andsaid means for supplying water, said throttling means being controlledby said float in such manner that, when the level in said containerrises, the supply of material is throttled and the water supply isincreased, and, when the level in said container sinks, the supply of'material is increased and the water supply is throttled.

ANDREAS BIFFAR.

